1. Field of the Invention
The present invention relates generally to electrical distribution equipment and conductors contained within enclosures referred to herein generally as cabinets, although such enclosures need not have doors to benefit from the present invention. The invention relates more particularly to passively controlling the effects of arc faults in electrical cabinets. Arc control referred to herein is not within the circuit breakers themselves, i.e. not bolted faults.
2. Discussion of the Known Art
The hazards of unexpected and/or uncontrolled arcing events, also called arc faults, in an electrical cabinet are well known and include potential damage to equipment and harm to personnel in the operating environment caused by arc flash and arc blast, hereinafter referred to for simplicity as arc blast. Both passive and active arc control means are known in the art. Passive means include directed venting of the arc blast energy and gasses out of the cabinet. Other passive means may include reinforcement of the cabinet structure in an effort to withstand the blast. Neither form of passive method limits fault duration or is easily retrofitable into existing switchgear cabinets. Active means usually include some form of sensing and a switching mechanism to control the current. Concerns with active means may include expense, nuisance trips, speed, and undetected system failures. Of course, the quicker the arc is controlled the less harm is likely to be done by the arcing event.